Leases - Components of Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Leases [Abstract]
Sublease income	$ (25)	$ (50)
Operating lease cost	171	318
Operating lease cost, net	146	268
Sublease income	(111)	(223)
Lease cost	107	216
Restructured lease cost, net	(4)	(7)
Interest on lease liabilities	1	1
Total lease cost, net	$ 143	$ 262